The invention is directed to an apparatus for degasifying a liquid, such as a flowing liquid medium. The invention is particularly directed to an apparatus for the deaeration of a flowing liquid medium such as water in a heat exchange cycle, e.g. forming a part of a heating system.
Hydraulic systems, particularly heating systems based upon heat exchange involving a flowing liquid medium, can never be entirely filled without eliminating the occurence of gaseous bubbles such as air bubbles within the liquid medium itself (e.g. water). Additionally, unwanted gas such as air or oxygen can enter such systems through leaks (e.g. in plastic pipes of a floor-type heating system) and through diffusion into the liquid medium. The gas such as air or oxygen entering a pipe carrying the liquid medium causes noise, corrosion of heating components such as the interior of the heating pipe itself, and reduced the overall effectiveness of a heating system or operation in which these pipes are disposed. Such problems have been conventionally overcome by continuously venting the heating system with suitably-placed escape valves. However, such continuous venting of a heating system is extremely time-consuming, cumbersome and inconvenient, and also inadequate for eliminating gaseous bubbles such as air from the flowing liquid medium (i.e. inadequate for accomplishing the degasification of the flowing liquid medium).
Automatic-type escape valves have been utilized to degasify the flowing liquid medium in such heating systems, these automatic escape valves being connected with the pipes carrying the heating liquid medium, and designed to vent air that has penetrated into the flowing liquid medium, via a float valve. However, it has been proven that such automatic-type escape valves are almost totally useless, since air being carried along within a cycling liquid medium such as water, will not at all enter the pipe provided in a separator of the escape valve, and thus the air so entrained in the flowing water medium will not escape therefrom through the valve.
In order to solve this particular problem, an absorption-degassing process distributed under the trademark "SPIROVENT" has been proposed. With the equipment of this process, the entire heating liquid medium flows across a degasifying container. The degassing container is provided with means for generating a laminar flow of the liquid medium, to enable gas or air bubbles to rise quite easily to the surface thereof. The apparatus of this "SPIROVENT" process is attached just after the heating boiler, i.e., at the point where the flowing water medium has its greatest temperature, so the flowing water will only have a slight susceptibility to reentraining gas such as air released during the overall flow process. Rising gas bubbles accumulate in an area of this apparatus which can be brought into contact with the atmosphere, by means of a float valve when the liquid level of the flowing water is lowered, to enable the gas such as air to escape when there is sufficient accumulation of the same.
Such a device as disclosed in this "SPIROVENT" process, was expected to eliminate gas or air bubbles from the water flowing in the heating cycle, by loading the flowing water cycle with liquid medium that has not been saturated with the gas or air, so that the air or gas trapped within the flowing, heating water cycle in the heating pipe, can be absorbed into the loaded medium to a point of saturation. The apparatus of the "SPIROVENT" process is located right after the boiler in the heating cycle, because it has been assumed that much less gas can be released from the flowing liquid or water medium at the temperature where the liquid has just exited from the heat exchanger. However, on the one hand, greater quantities of air will still tend to exist at other points in the flowing liquid cycle, for example in the circulating pump. On the other hand, the difference in solubility corresponding to the small difference existing between the return temperature of the liquid heating medium just after a heat exchanger and the flow temperature where the "SPIROVENT" apparatus is located, is extremely small, so that effective absorption of gas or air bubbles into the flowing liquid medium within a heating cycle, cannot be expected with the process and apparatus of "SPIROVENT".